From fac99d97469e7f91102f97101bea620e5f073196 Mon Sep 17 00:00:00 2001
From: Paul Mundt <lethal@linux-sh.org>
Date: Tue, 3 Oct 2006 14:13:09 +0900
Subject: [PATCH] sh: Fixup __raw_read_trylock().
generic__raw_read_trylock() was broken, fix up the __raw_read_trylock()
implementation for something sensible. Taken from m32r, which has the
same use cases.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
---
include/asm-sh/spinlock.h | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/include/asm-sh/spinlock.h b/include/asm-sh/spinlock.h
index 54458fd249815..2586eef07d572 100644
--- a/include/asm-sh/spinlock.h
+++ b/include/asm-sh/spinlock.h
@@ -88,7 +88,14 @@ static inline void __raw_write_unlock(raw_rwlock_t *rw)
__raw_spin_unlock(&rw->lock);
}
-#define __raw_read_trylock(lock) generic__raw_read_trylock(lock)
+static inline int __raw_read_trylock(raw_rwlock_t *lock)
+{
+ atomic_t *count = (atomic_t*)lock;
+ if (atomic_dec_return(count) >= 0)
+ return 1;
+ atomic_inc(count);
+ return 0;
+}
static inline int __raw_write_trylock(raw_rwlock_t *rw)
{
--
2.30.2